Spectroscopic and Thermal Analysis of Synthesized Inorganic Phosphate Glass Fertilizers: A Comprehensive Characterization Study

A new class of slow-release inorganic glass fertilizer was developed using the melt- quenching fashion to enable sustained nutrient delivery for different crop species. The glass formulations were melted at a temperature range of 750 – 760 °C, with a soaking period of 30 minutes. Their amorphous structure was verified by X-ray Diffraction (XRD). Fourier Transform Infrared (FTIR) spectroscopy, conducted in the 400 – 4000 cm⁻¹ range, revealed crucial optical phonon modes characteristic of the phosphate matrix, with notable absorption bands observed at 413, 471, 551, 760, 879, 920, 1087, 1110, 2193 – 2870, and 3440 – 3500 cm⁻¹. The sursurface morphology was examined using Scanning Electron Microscopy (SEM), and essential composition was assessed via X-ray fluorescence (XRF). Incorporation of MoO₃ into the phosphate glass matrix introduced Raman-active modes between 800 and 1200 cm⁻¹, attributed to symmetric and asymmetric stretching modes of molybdenum-ground polyhedral units. Specifically, the Raman peak at 996 cm⁻¹ was assigned to symmetric Mo=O stretching in distorted MoO₆ octahedra. Thermal behaviour and stability were evaluated using Differential Thermal Analysis (DTA) and Thermogravimetric Analysis (TGA). The findings emphasize the promise of phosphate-ground glass systems as effective, long-lasting, and sustainable matrices for agricultural application.